On Sept. 15, North Korea launched a ballistic missile that flew over Hokkaido, Japan. This is the second time a North Korean missile passed over Japan’s airspace. Less than two weeks ago, North Korea claimed to have successfully detonated a hydrogen bomb, representing a major leap in Pyongyang’s nuclear capability.

If you are the president of the United States, how would you counter North Korea’s nuclear threat?

Being passive is not an option. North Korea has nuclear bombs. Moreover, according to aconfidential assessment by the U.S. intelligence community, North Korea has likely mastered nuclear warhead miniaturization technology, making possible missile-deliverable atomic bombs.

If North Korea develops reliable intercontinental ballistic missiles (ICBM), the globe will be taken hostage by Kim Jong Un. The intensive missile tests since 2014 indicate that developing an ICBM is a priority for the regime. The Hwasong-12 missile North Korea fired on Sept. 15 traveled 2,300 miles, putting Guam, a U.S. territory, within its range. If North Korea’s ICBM program goes unchecked, it is only a matter of time before Kim Jong Un has nuclear missiles that can reach the whole continental United States.

Casualties Deter Making War

An open war with North Korea is nearly impossible, at least for now. The United States and its allies have the capability, but they lack the will. The South Korean President, Moon Jae-in, is firmly against a war with North Korea. He hassaid he would “prevent war at all costs,” and favors sanctions.

The THAAD missile defense system, seen this file photo, passed another test on July 30, shooting down an ICBM over the Pacific. (Lockheed Martin)

One will understand his reluctance better by opening a map of the Korean peninsula: approximately 25 million people live in Seoul, 35 miles from the North-South border. It is generallybelieved that the North has amassed a huge amount of artillery on the border, which could turn the Seoul metropolitan area into a “sea of fire” that could result in up to a million civilian casualties. Those potential casualties make South Korea opposed to war, and without its cooperation in military operations, the United States is in a bind.

A few days after North Korea’s purported thermonuclear test on Sept. 3 (whether North Korea exploded an atomic bomb, or a more powerful hydrogen bomb, is in dispute), South Korea reportedly created a special military “decapitation unit” aiming at assassinating Kim Jong Un. But this is most likely a deterrence tactic, not a credible threat. If the South were serious, the whole operation would be classified.

North Korean leader Kim Jong Un provides guidance on a nuclear weapons program in this undated photo released by North Korea’s Korean Central News Agency (KCNA) in Pyongyang on Sept. 3, 2017. (KCNA via REUTERS)

Moreover, Kim is a difficult target. He is easily the most secretive dictator in the world. He has never granted any interview with journalists. Nobody from outside knows where he lives and works. The state news agency in North Korea routinely releases Kim’s pictures and videos days after the events.

A failed assassination attempt would certainly draw retaliation from the North, with the potential to escalate to a nuclear war. Even if Kim is assassinated, no one knows for sure whether North Korea would launch nukes to avenge his death.

Appeasement Has Failed

But appeasement hasn’t worked either. Called the Sunshine Policy, it was tried by South Korea from 1998 to 2008. In exchange for North Korea’s diplomatic and economic cooperation, South Korea turned a blind eye to the North’s horrendous human rights abuses and sought to downplay its constant military threats.

More than10 armed conflicts between the two Koreas didn’t stop the South from sending massive financial and food aid to the North each year. How did North Korea return the favor? By conducting its first nuclear test in 2006. South Korea failed to endear the North Korea regime, and, in the meantime, its traditional alliance with the United States started to fray. The Sunshine Policy was suspended in 2008 and officiallydeclared a failure in 2010.

Could sanctions against North Korea work? If correctly applied, sanctions have the potential for debilitating Kim’s regime and forcing Pyongyang back to the negotiating table. But so far sanctions against North Korea have produced little or no positive results, largely due to China’s sabotage. One glaring example is the Dandong-Sinuijupipeline, which supplies roughly 90 percent of Pyongyang’s annual crude oil needs.

The beneficiaries of the pipeline are believed to include the North Korean government, military, and industries. China has resisted calls for shutting down the pipeline for years. After the purported hydrogen bomb test, China insisted the pipeline be explicitly exempted from the sanctions drafted by the United States, resulting in the U.N. Security Council passing a resolution that lacked the most powerful sanction that could be imposed on North Korea.

China’s Strategic Interests

China has many strategic interests in maintaining the status quo in North Korea.

First of all, China sees North Korea as a buffer zone keeping the U.S. military away from its borders. If the Kim regime is toppled and the two Koreas peacefully unify, China would lose that barrier.

Secondly, China is happy to see North Korea making trouble for the United States and its Asian allies, tying up their attention and resources. However, after Kim conducted a series of nuclear tests in China’s backyard, it realized its tactics had backfired.

Finally, China fears that if serious instability erupts in North Korea, it would need to cope with a large population of North Korean refugees.

Economic Leverage on China

As long as China continues to be the largest enabler of North Korea, sanctions won’t stop Kim from pursuing his nuclear ambitions. How to bring China into the fold? If there is one thing that China wants the most, it is economic growth.

After 30 years of rapid expansion, it is generally accepted that China’s economy is entering a phase of slower growth, dubbed a “new normal” by China officials. Three major driving forces behind China’s GDP growth are domestic consumption, investment, and net export. The net export is one area China desperately wants to improve. In the past few years, the slowing of net exports have often been a drag on GDP growth.

The United States is China’s largest export market. In 2016, the goods and services the United Statesimported from China totaled US$478.9 billion, accounting for 18.4 percent of total imports; the goods and services the United States exported to China were worth $169.3 billion, roughly 8 percent of overall U.S.exports in 2016.

U.S. President Donald Trump and Chinese leader Xi Jinping walk together at the Mar-a-Lago estate in West Palm Beach, Fla., on April 7, 2017. (JIM WATSON/AFP/Getty Images)

In China, export-related industries employed more than 79 million people in 2009. If China stops buying our products and services, the U.S. economy may experience a small bump, but will be able to recover. If we stop buying everything made in China, however, China may likely have an economic heart attack.

The United States has plenty of leverage in negotiations with China. China should be given two choices: either completely stop providing material support to the Kim regime, or face tariffs, and border adjustment taxes and other non-tariff barriers in trade with the United States. If China doesn’t want to regress to isolation and give up all economic gain, the choice is fairly obvious.

Interception

The international sanctions are passive measures. The termination of Kim’s nuclear weapon programs can be accelerated by actively intercepting North Korea’s missiles. Test launches are meant to accumulate valuable data and know-how, so that missiles can cover longer distances, improve stability and reliability, and hit targets with more precision.

The international community should unite and declare the international waters surrounding the two Koreas as off limits to Pyongyang’s missiles; any missile fired by North Korea will be shot down the moment it enters international territory.

A soldier films North Korean soldiers, officers and high ranking officials attending a military parade marking the 105th birth anniversary of country’s founding father Kim Il Sung in Pyongyang, North Korea on April 15, 2017. (REUTERS/Damir Sagolj)

With an oil embargo, Kim Jong Un’s military would have no fuel to move troops and heavy equipment; North Korea would be less likely to be able to launch missiles, or conduct nuclear tests. “North Korea would not survive on its own for three months and everything in North Korea would be paralyzed”, Cho Bong-hyun, an expert on North Korea’s economy,told Reuters.

With an anti-missile shield erected around North Korea, the regime’s ability to test long range missiles is denied. There is a fairly good chance North Korea’s nuclear weapon programs can be halted for good.

A nuclear North Korea should never be tolerated, normalized, or accepted. I understand the desire of some to coexist with the North. But no one in their right mind would keep a rabid dog as a pet. Under the Kim family, North Korea’s nuclear capability has grown over the past two decades like a cancer.

Now is the time to remove the threat. U.S. leadership is absolutely crucial to achieve this goal. Fortunately, the days of America “leading from behind” are over. In a world of indifference and inaction, America will once again save the day.